Broodspinner

The graveyard-count payoff has a long lineage (Tarmogoyf sizes a body by card types, and countless aristocrats decks measure their yard some other way), but this one converts the tally into a wide board rather than a single stat line, which changes what the graveyard is being counted for. The entry surveil quietly does the setup: two cards toward the graveyard, filling the very resource the sacrifice ability later reads. That is the whole engine in miniature. You spend the early turns fixing the graveyard's card-type diversity (creature, instant, land, enchantment, and so on), then cash it in for a flock of flying Insects. Six mana plus the tap and the sacrifice is a real tax, and it happens at instant speed only in the sense that any activated ability can, so the token burst is a payoff you build toward, not a surprise. The 2/3 reach body is the part that keeps the card honest before you get there: it blocks the early fliers the tokens will later mimic, which means the card is defensively useful on turn two and offensively useful once the graveyard is stocked. Where most token-makers key off a fixed number or a resource you spend down, this one grows with a pile you were filling anyway, and the surveil makes sure you were filling it deliberately.